Performance Of Pulse Oximetry Research Articles

Tissue mimicking materials and finger phantom design for pulse oximetry.

Pulse oximetry represents a ubiquitous clinical application of optics in modern medicine. Recent studies have raised concerns regarding the potential impact of confounders, such as variable skin pigmentation and perfusion, on blood oxygen saturation measurement accuracy in pulse oximeters. Tissue-mimicking phantom testing offers a low-cost, well-controlled solution for characterizing device performance and studying potential error sources, which may thus reduce the need for costly in vivo trials. The purpose of this study was to develop realistic phantom-based test methods for pulse oximetry. Material optical and mechanical properties were reviewed, selected, and tuned for optimal biological relevance, e.g., oxygenated tissue absorption and scattering, strength, elasticity, hardness, and other parameters representing the human finger's geometry and composition, such as blood vessel size and distribution, and perfusion. Relevant anatomical and physiological properties are summarized and implemented toward the creation of a preliminary finger phantom. To create a preliminary finger phantom, we synthesized a high-compliance silicone matrix with scatterers for embedding flexible tubing and investigated the addition of these scatterers to novel 3D printing resins for optical property control without altering mechanical stability, streamlining the production of phantoms with biologically relevant characteristics. Phantom utility was demonstrated by applying dynamic, pressure waveforms to produce tube volume change and resultant photoplethysmography (PPG) signals. 3D printed phantoms achieved more biologically relevant conditions compared to molded phantoms. These preliminary results indicate that the phantoms show strong potential to be developed into tools for evaluating pulse oximetry performance. Gaps, recommendations, and strategies are presented for continued phantom development.

Comparative analysis of signal accuracy of three SpO2 monitors during motion and low perfusion conditions

To compare pulse oximetry performance during simulated conditions of motion and low perfusion in three commercially available devices: GE HealthCare CARESCAPE ONE TruSignal SpO2 Parameter, Masimo RADICAL-7 and Medtronic Nellcor PM1000N. After IRB approval, 28 healthy adult volunteers were randomly assigned to the motion group (N = 14) or low perfusion (N = 14) group. Pulse oximeters were placed on the test and control hands using random assignment of digits 2–5. Each subject served as their own control through the series of repeated pair-wise measurements. Reference co-oximetry oxyhemoglobin (SaO2) measurements from the radial artery were also obtained in the motion group. SpO2 readings were compared between the test and control hands in both groups and to SaO2 measurements in the motion group. Accuracy was assessed through testing of accuracy root-mean squared (ARMS) and mean bias. In the simulated motion test group the overall Accuracy Root Mean Square (ARMS) versus SaO2 was 1.88 (GE), 1.79 (Masimo) and 2.40 (Nellcor), with overall mean bias of − 0.21 (Masimo), 0.45 (GE), and 0.78 (Nellcor). In the motion hand, ARMS versus SaO2 was 2.45 (GE), 3.19 (Masimo) and 4.15 (Nellcor), with overall mean bias of − 0.75 (Masimo), − 0.01 (GE), and 0.04 (Nellcor). In the low perfusion test group, ARMS versus the control hand SpO2 for low PI was 3.24 (GE), 3.48 (Nellcor) and 4.76 (Masimo), with overall bias measurements of − 0.53 (Nellcor), 0.96 (GE) and 1.76 (Masimo). Experimental results for all tested devices met pulse oximetry regulatory and testing standards requirements. Overall, SpO2 device performance across the three devices in this study was similar under both motion and low perfusion conditions. SpO2 measurement accuracy degraded for all three devices during motion as compared to non-motion. Accuracy also degraded during normal to low, very low, or ultra low perfusion and was more pronounced compared to the changes observed during simulated motion. While some statistically significant differences in individual measurements were found, the clinical relevance of these differences requires further study.

Oxygen saturation targets for adults with acute hypoxemia in low and lower-middle income countries: a scoping review with analysis of contextual factors.

Knowing the target oxygen saturation (SpO2) range that results in the best outcomes for acutely hypoxemic adults is important for clinical care, training, and research in low-income and lower-middle income countries (collectively LMICs). The evidence we have for SpO2 targets emanates from high-income countries (HICs), and therefore may miss important contextual factors for LMIC settings. Furthermore, the evidence from HICs is mixed, amplifying the importance of specific circumstances. For this literature review and analysis, we considered SpO2 targets used in previous trials, international and national society guidelines, and direct trial evidence comparing outcomes using different SpO2 ranges (all from HICs). We also considered contextual factors, including emerging data on pulse oximetry performance in different skin pigmentation ranges, the risk of depleting oxygen resources in LMIC settings, the lack of access to arterial blood gases that necessitates consideration of the subpopulation of hypoxemic patients who are also hypercapnic, and the impact of altitude on median SpO2 values. This process of integrating prior study protocols, society guidelines, available evidence, and contextual factors is potentially useful for the development of other clinical guidelines for LMIC settings. We suggest that a goal SpO2 range of 90-94% is reasonable, using high-performing pulse oximeters. Answering context-specific research questions, such as an optimal SpO2 target range in LMIC contexts, is critical for advancing equity in clinical outcomes globally.

Performance of Pulse Oximetry in Screening of Critical congenital Heart Diseases: Meta-analysis of meta-analytic studies and systematic review.

Performance of Pulse Oximetry in Screening of Critical congenital Heart Diseases: Meta-analysis of meta-analytic studies and systematic review.

1030: OCCULT HYPOXEMIA AND PULSE OXIMETRY PERFORMANCE ACROSS SKIN PIGMENTATION GROUPS

Introduction: Pulse oximetry accuracy reportedly varies by race (Henry et al. Crit Care Med 2022; Sjoding et al. N Engl J Med 2021). However, since race correlates weakly with skin pigmentation, it is more precise to evaluate pulse oximeter performance by skin pigmentation (He et al, J Am Acad Dermatol 2014). The purpose of this analysis was to assess Nellcor™ pulse oximetry performance across varying skin pigmentations for blood oxygen saturations between 80-92%, when occult hypoxemia, with errors of ≥4% occur between SpO2 and SaO2, can occur (Henry et al. Crit Care Med 2022). Methods: This retrospective analysis included Medtronic-sponsored healthy adult volunteer studies conducted between July 2003 and February 2017. In each study, a Nellcor™ pulse oximeter (MAXA, MAXN, MAXFAST, or FLEXMAX) measured arterial blood oxygenation, in comparison to co-oximeter-measured SaO2 (ISO 80601-2-61 aligned) during controlled hypoxia. Skin pigmentation was visually assessed using a 4-level scale: very light, olive, dark olive, and extremely dark. Results: 69 very light or olive volunteers (light skin pigmentation) and 19 dark olive or extremely dark volunteers (dark skin pigmentation) were included. For arterial oxygen saturations between 80-92%, the light and dark skin pigmentation groups had bias of 0.05% (95%CI 0.01-0.09) and 0.30% (95%CI 0.22-0.38); precision of 1.39% (95%CI 1.36-1.41) and 1.54% (95%CI 1.49-1.60); and root-mean square deviation (RMSD) of 1.39% and 1.57%. The percentage of data points with SpO2-SaO2 error ≥4%, the minimum required for occult hypoxemia, was 0.79% (N=40/5098) and 0.54% (N=8/1518) for the light and dark skin pigmentation groups. Conclusions: In both groups, RMSD remained within device specifications (±2), with increased error in individuals with dark skin pigmentation. For both skin pigmentation groups, observed errors of ≥4% occurred < 1% between 80-92% SpO2, whereas the literature has reported occult hypoxemia rates of 3.6%-6.6% (Henry et al. Crit Care Med 2022). This discrepancy may be due to differences in patient type, timing of SpO2/SaO2 readings, the amount of motion noise across studies, and the limited sample size in this retrospective analysis. Additional research is needed to characterize pulse oximetry performance and ensure accuracy across all skin pigmentations.

Newborn Screening for Critical Congenital Heart Disease in a Low-Resource Setting; Research Protocol and Preliminary Results of the Tanzania Pulse Oximetry Study.

Background:Critical Congenital Heart Disease (CCHD) is the leading cause of early new-born mortality. Its early detection and intervention is crucial for the survival of affected new-born. Pulse Oximetry (POX) has shown to be one of the feasible, accurate and cost-effective tools in screening CCHD in developed nations, it is yet to be practiced and established as standard of care in a low-resource setting.Objectives:This paper reports on the research protocol and preliminary results of an ongoing study regarding the performance of POX in detecting CCHD in new-borns in a low resource setting. Secondary objectives include investigating the burdens of CCHD and outcome at 12 months of age.Methods:The Tanzanian Pulse Oximetry Study (TPOXS) is a prospective cohort study which plans to enrol 30,000 mothers and new-borns delivered at two referral hospitals in Tanzania. New-borns are offered POX test 12 hours after birth, those positively undergoes echocardiography examinations. Confirmed with CCHD are placed under observation for up to first birthday.Results:During a 5-months pilot period, a total of 1,592 infants at the Muhimbili National Hospital, received POX test .65% of them were post-caesarean section and 52% being male. Most babies delivered through Spontaneous Vertex Delivery (SVD) were promptly discharge and did not get screened. The detection-rate of CCHD was 2.5 per 1,000 live births (at 95% confidence interval [CI] 0.9 to 6.7 per 1000 live birth); with a POX false positive rate of 0.6%. Seven false-positive infants out of 10 were found to carry significant other neonatal conditions, including persistent pulmonary hypertension of the new-born, transient tachypnoeic and neonatal sepsis.Conclusion:This paper provides the protocol of the ongoing TPOXS with the preliminary results showing prevalence matching closely the global data. It shows acceptability of POX screening for CCHD in a well-prepared low resource setting.Highlight:This study addresses the utilization of pulse oximeter in detecting critical congenital heart disease (CCHD) in a low-resource setting (such as sub-Saharan African countries).

Relying on pulse oximetry to avoid hypoxaemia and hyperoxia: A multicentre prospective cohort study in patients with circulatory failure

PurposeThe purpose of this study was to assess the predictive performance of pulse oximetry (SpO2) to rule out hypoxaemia and hyperoxia in critically ill patients. MethodsSpO2, arterial oxygenation (SaO2), and arterial partial pressure of oxygen (PaO2) were prospectively and simultaneously measured every 6 h during the first 24 h of intensive care unit admission in a multicentre cohort of critically ill patients suffering acute circulatory failure. Likelihood ratios associated with different cutoff values of SpO2 to rule out hypoxaemia (SaO2 < 90% or PaO2 < 60 mmHg) or hyperoxia (SaO2 > 95% or PaO2 > 100 mmHg) and post-test probabilities were calculated. Mean bias between SpO2 and SaO2 and agreement interval were calculated. Area under the receiver operating characteristics associated with SpO2 to predict different threshold values of SaO2 and PaO2 were calculated. ResultsFive hundred seventy-one patients (mean [standard deviation] Simplified Acute Physiology Score II: 58.7 [20.1]; mechanically ventilated 75.6%) with 2643 available SaO2 and PaO2 samples and corresponding 2643 SpO2 values were analysed. Mean bias between SpO2 and SaO2 was 1.1%, and its agreement interval ranged from −8.2 to +11.1%. SpO2 cutoff values of 88%, 90%, and 92% left the possibility that 8%–13% of patients had hypoxaemia. SpO2 < 95% left the possibility that 31% of patients had hyperoxia. All calculated areas under the receiver operating characteristics showed a lower limit of their 95% confidence interval below 0.85 ConclusionIn this cohort of patients with circulatory failure, SpO2 had poor discriminative ability to rule out hypoxaemia and hyperoxia. Overconfidence upon SpO2 monitoring may be dangerous.

Success and time implications of SpO2 measurement through pulse oximetry among hospitalised children in rural Bangladesh: Variability by various device-, provider- and patient-related factors.

BackgroundHypoxaemia is one of the strongest predictors of mortality among children with pneumonia. It can be identified through pulse oximetry instantaneously, which is a non-invasive procedure but can be influenced by factors related to the specific measuring device, health provider and patient. Following WHO's global recommendation in 2014, Bangladesh decided to introduce pulse oximetry in paediatric outpatient services, ie, the Integrated Management of Childhood Illness (IMCI) services in 2019. A national committee updated the existing IMCI implementation package and decided to test it by assessing the pulse oximetry performance of different types of assessors in real-life inpatient settings.MethodsWe adopted an observational design and conducted a technology assessment among children admitted to a rural district hospital. Eleven nurses and seven paramedics received one-day training on pulse oximetry as assessors. Each assessor performed at least 30 pulse oximetry measurements on children with two types of handheld devices. The primary outcome of interest was obtaining a successful measurement of SpO2, defined as observing a stable (±1%) reading for at least 10 seconds. Performance time, ie, time taken to obtain a successful measurement of SpO2 was considered the secondary outcome of interest. In addition, we used Generalized Estimating Equation to assess the effect of different factors on the pulse oximetry performance.ResultsThe assessors obtained successful measurements of SpO2 in all attempts (n = 1478) except one. The median time taken was 30 (interquartile range (IQR) = 22-42) seconds, and within 60 seconds, 92% of attempts were successful. The odds of obtaining a successful measurement within 60 seconds were 7.3 (95% confidence interval (CI) = 3.7-14.2) times higher with a Masimo device than a Lifebox device. Similarly, assessors aged >25 years were 4.8 (95% CI = 1.2, 18.6) times more likely to obtain a successful measurement within 60 seconds. The odds of obtaining a successful measurement was 2.6 (95% CI = 1.6, 4.2) times higher among children aged 12-59 months compared to 2-11 months.ConclusionsOur study indicated that assessors could achieve the necessary skills to perform pulse oximetry successfully in real-life inpatient settings through a short training module, with some effect of device-, provider- and patient-related factors. The National IMCI Programme of Bangladesh can use these findings for finalising the national IMCI training modules and implementation package incorporating the recommendation of using pulse oximetry for childhood pneumonia assessment.

Diagnostic Performance of Carbon Monoxide Testing by Pulse Oximetry in the Emergency Department.

Carbon monoxide (CO) exposure causes roughly 40,000 emergency department (ED) visits annually and is commonly misdiagnosed. Whereas the standard method of carboxyhemoglobin (HbCO) measurement utilizes blood gas analysis, a noninvasive, FDA-cleared alternative exists. We evaluated the performance of pulse oximetry (SpCO) for identification of CO exposure in ED patients. We compared pulse oximetry to blood HbCO levels in a prospective observational study of adult and pediatric subjects recruited from the ED. Nurses screened a convenience sample of patients and referred those with SpCO ≥ 10% to research staff. Researchers also approached individuals who presented with signs and symptoms of CO toxicity. We determined diagnostic performance with a Bland-Altman analysis and calculated sensitivity and specificity for detection of elevated HbCO at thresholds of ≥ 10% and ≥ 15%. To optimize the potential sensitivity of SpCO for detection of CO toxicity, research technicians performed 3 SpCO readings within 5 min of the blood draw for laboratory measurement. A positive SpCO test was defined as any SpCO ≥ 10%. 42,000 patients were screened, 212 were evaluated, and 126 subjects were enrolled. Median HbCO level was 6% (range 1.6-21.9%). Limits of agreement were -10.3% and 8.1%. Of 23 individuals with elevated HbCO ≥ 10%, 13 were not suspected based on clinical assessment. Critically elevated HbCO was present in 6 individuals. Based on our a priori threshold of 10% for a positive test, pulse oximetry identified 14 of 23 subjects with HbCO ≥ 10%, with a sensitivity of 61% (95% CI 39-80%) and a specificity of 86% (95% CI 78-92%), and 5 of 6 subjects with HbCO ≥ 15%, with a sensitivity of 83% (95% CI 36-100%) and a specificity of 81% (95% CI 73-87%). Pulse oximetry underestimated HbCO and produced false negative results (ie, SpCO < 10% for all three measurements) in 17% of ED subjects with elevated HbCO ≥ 15%. Triage screening with pulse oximetry detected cases of elevated HbCO that were not suspected by the clinical provider.

Retrospective study on the usefulness of pulse oximetry for the identification of young children with severe illnesses and severe pneumonia in a rural outpatient clinic of Papua New Guinea.

ObjectiveThis secondary analysis of data of a randomized controlled trial (RCT) retrospectively investigated the performance of pulse oximetry in identifying children with severe illnesses, with and without respiratory signs/symptoms, in a cohort of children followed for morbid episodes in an intervention trial assessing the efficacy of Intermittent Preventive Treatment for malaria in infants (IPTi) in Papua New Guinea (PNG) from June 2006 to May 2010.SettingThe IPTi study was conducted in a paediatric population visiting two health centres on the north coast of PNG in the Mugil area of the Sumkar District.ParticipantsA total of 669 children visited the clinic and a total of 1921 illness episodes were recorded. Inclusion criteria were: age between 3 and 27 months, full clinical record (signs/symptoms) and pulse oximetry used systematically to assess sick children at all visits. Children were excluded if they visited the clinic in the previous 14 days.OutcomesThe outcome measures were severe illness, severe pneumonia, pneumonia, defined by the Integrated Management of Childhood Illness (IMCI) definitions, and hospitalization.ResultsOut of 1921 illness episodes, 1663 fulfilled the inclusion criteria. A total of 139 severe illnesses were identified, of which 93 were severe pneumonia. The ROC curves of pulse oximetry (continuous variable) showed an AUC of 0.63, 0.68 and 0.65 for prediction of severe illness, severe pneumonia and hospitalization, respectively. Pulse oximetry allowed better discrimination between severe and non-severe illness, severe and non-severe pneumonia, admitted and non-admitted patients, in children ≤12-months of age relative to older patients. For the threshold of peripheral arterial oxygen saturation ≤ 94% measured by pulse oximetry (SpO2), unadjusted odds ratios for severe illness, severe pneumonia and hospitalization were 6.1 (95% Confidence Interval (CI) 3.9–9.8), 8.5 (4.9–14.6) and 5.9 (3.4–10.3), respectively.ConclusionPulse oximetry was helpful in identifying children with severe illness in outpatient facilities in PNG. A SpO2 of 94% seems the most discriminative threshold. Considering its affordability and ease of use, pulse oximetry could be a valuable additional tool assisting the decision to admit for treatment.

Role of pulse oximetry in screening of critical congenital heart disease in asymptomatic neonates

Background: Neonatal screening for critical congenital heart disease can aid in early recognition and improved outcome of critical congenital heart diseases. Our aim was to assess the performance of pulse oximetry as a screening tool for the detection of critical congenital heart diseases in asymptomatic neonates.Methods: Our study was a hospital based prospective study conducted on all asymptomatic neonates brought to neonatology section of tertiary care hospital. Pulse oximetric screening was performed by a single determination of postductal oxygen saturation in all asymptomatic newborns that fulfilled the inclusion criteria. To ensure universal screening, the timing of pulse oximetric determination was &gt;24 hrs age. All newborns found to have a post-ductal saturation ≤95% underwent additional evaluation by echocardiography. Data regarding true and false positives as well as negatives was collected and sensitivity, specificity and predictive values of pulse oximetry for screening of asymptomatic newborns with congenital heart disease were determined.Results: 2600 neonates were screened and 7 cases of CCHD were diagnosed, giving a prevalence of 0.27 %. Sensitivity, specificity, positive predictive value and negative predictive value of pulse oximetry for detection of CCHD were 77.78%, 99.92%, 77.78% and 99.92%, respectively.Conclusions: We conclude that pulse oximetry is safe, easily available and reasonably accurate for screening of CCHD with sensitivity better than antenatal screening and clinical examination. Its specificity and negative predictive value are very high, making second stage confirmatory echocardiography highly cost-effective. Thus, the results of this study add to the already growing body of evidence that strongly supports introduction of pre discharge pulse oximetry screening as a routine procedure in healthy newborn babies.

Pulse Oximetry Overestimates Oxygen Saturation in COPD.

Measurement of oxygen saturation with a handheld pulse oximeter is widely practiced as a surrogate to invasive arterial blood gas analysis. Oxygen saturation is an important parameter in cases of COPD, but there are insufficient data on the role of pulse oximetry in patients with COPD, moreso in diseases across its spectrum, such as chronic bronchitis and emphysema. We assessed the performance of pulse oximetry in acute respiratory failure of patients with COPD. This was a cross-sectional, observational study. We studied 50 subjects with COPD admitted to the Government General Hospital, a 1,000-bed tertiary referral center in Guntur, India, from June 2013 to July 2013. Simultaneous reading of S(pO2) by a handheld pulse oximeter and S(aO2) by an automated arterial blood gas analyzer were taken. Pulse oximetry was sufficiently sensitive (84.60%) to hypoxemia in respiratory failure to be used in clinical situations. The mean difference (bias) between SaO2 and S(pO2) was -3.98 (95% CI -4.68 to 3.28). There was less sensitivity (82% vs. 85%) and positive predictive value (69% vs. 85%) of the pulse oximeter to respiratory failure in subjects with chronic bronchitis versus emphysema. Pulse oximetry performed poorly in comparison with the invasive arterial blood gas analysis. The variability of the readings was greater in the subjects with chronic bronchitis than in those with emphysema.

Pulse oximetry performance in mechanically ventilated newborn infants

Pulse oximetry is widely used to target oxygenation in newborn infants. In a retrospective chart review of 138 mechanically ventilated infants, pulse oximetry overestimated blood oxygen saturation compared to arterial blood gas analyses. Despite improvements in pulse oximeter technology, pulse oximetry performance in sick newborns should still be under scrutiny.

Ventilación mecánica no invasiva. Reflexiones sobre la monitorización a domicilio

CIBERES, Ciber de enfermedades respiratorias, Spain Home-based noninvasive ventilation (NIV) was initiated in the early nineties in our environment as a treatment for patients with chronic respiratory failure, secondary to restrictive ventilatory disorders or neuromuscular disease. Subsequently, NIV also proved effective in patients with obesity-related hypoventilation syndromes, and to a lesser extent in some patients with chronic obstructive pulmonary disease in stable phase. There was a simultaneous growth in interest in whether the selected parameters suited the patients’ needs when using NIV in the home setting. Thus, the use of continuous overnight pulse oximetry monitoring as the gold standard for home monitoring in centers prescribing ventilation became widespread. The main issue with pulse oximetry has undoubtedly been its lack of specificity for correlation with certain patterns of patient–ventilator interaction. In other words, the effects of adverse events (desaturation) were detected, but there was a limited understanding of the underlying causes, and therefore of the potential solutions. In order to improve the performance of pulse oximetry, a series of simplified polygraphic systems have appeared in recent years, mostly in association with the ventilator manufacturers. These systems provide a set of data on the patient’s respiratory mechanics that can be downloaded from the ventilator’s internal memory. The main purpose is to provide the clinician with additional information on the potential reasons for inadequate ventilation periods and the pathophysiological causes (unintentional interface leaks, uncorrected upper airway episodes, asynchrony, etc.). Over the years, almost all manufacturers of ventilation systems have developed their own download system and data display. 1 However, in our view, the performance and reliability of these devices, which are widely used today, should be analyzed in depth. The first premise to be considered by the clinician is that a number of values provided by these software systems are not measured directly. In single-tube systems, the most widely used in home

Pulse Oximetry Screening for Critical Congenital Heart Defects in Asymptomatic Newborn Babies

Summary Background Screening for critical congenital heart defects in newborn babies can aid in early recognition, with the prospect of improved outcome. We assessed the performance of pulse oximetry as a screening method for the detection of critical congenital heart defects in asymptomatic newborn babies. Methods In this systematic review, we searched Medline (1951–2011), Embase (1974–2011), Cochrane Library (2011), and Scisearch (1974–2011) for relevant citations with no language restriction. We selected studies that assessed the accuracy of pulse oximetry for the detection of critical congenital heart defects in asymptomatic newborn babies. Two reviewers selected studies that met the predefined criteria for population, tests, and outcomes. We calculated sensitivity, specificity, and corresponding 95% CIs for individual studies. A hierarchical receiver operating characteristic curve was fitted to generate summary estimates of sensitivity and specificity with a random effects model. Findings We screened 552 studies and identified 13 eligible studies with data for 229 421 newborn babies. The overall sensitivity of pulse oximetry for detection of critical congenital heart defects was 76·5% (95% CI 67·7–83·5). The specificity was 99·9% (99·7–99·9), with a false-positive rate of 0·14% (0·06–0·33). The false-positive rate for detection of critical congenital heart defects was particularly low when newborn pulse oximetry was done after 24 h from birth than when it was done before 24 h (0·05% [0·02–0·12] vs 0·50 [0·29–0·86]; p=0·0017). Interpretation Pulse oximetry is highly specific for detection of critical congenital heart defects with moderate sensitivity, that meets criteria for universal screening. Funding None.

Pulse oximetry screening for critical congenital heart defects in asymptomatic newborn babies: a systematic review and meta-analysis

Objective: This study assessed the performance of pulse oximetry as a screening method for the detection of critical congenital heart defects (CHD) in asymptomatic newborn babies. Background: Screening for critical congenital heart defects in newborn babies can aid in early recognition, which may lead to improved outcome. The potential predictive value of using pulse oximetry to screen for significant cyanotic CHD in newborns has been unclear. One difficulty of determining the potential value of universal screening of newborns with pulse oximetry from previous studies is that the relative infrequency of CHD made any individual study less able to demonstrate benefit. This meta-analysis with 229,421 newborn babies makes this a more powerful study. Methods: In this meta-analysis, the authors searched Medline (1951–2011), Embase (1974–2011), Cochrane Library (2011), and SciSearch (1974–2011) for studies that assessed the accuracy of pulse oximetry for the detection of critical CHD in asymptomatic newborn babies. Two reviewers selected studies that met the predefined criteria for population, tests, and outcomes, and sensitivity, specificity, and corresponding 95% CIs for individual studies were determined. Results: This meta-analysis identified 13 studies, published from 2001 to 2011, that screened 229,421 asymptomatic newborn infants for critical CHD (defined as disorders from which infants died or required invasive procedures or surgery in the first 28 days of life). The overall sensitivity of pulse oximetry for detection of critical CHD was 76.5%. The specificity was 99.9%, with a false-positive rate of 0.14%. Measurement of pulse oximetry before 24 h of age improved sensitivity from 77.5% to 84.8% (a nonsignificant difference) but increased the false-positive rate from 0.05% to 0.5% (a significant difference; p = .0017). Location of the pulse oximeter probe did not affect sensitivity or the frequency of false-positive results. Thangaratinam and colleagues concluded that pulse oximetry is a highly specific test for detection of critical CHD in newborn infants, and that the false-positive rate is low, especially when done after 24 h of age. Conclusion: Pulse oximetry is highly specific and moderately sensitive for detection of critical CHD and it meets the criteria for universal screening.

Pulse oximetry screening for critical congenital heart defects in asymptomatic newborn babies: a systematic review and meta-analysis

Screening for critical congenital heart defects in newborn babies can aid in early recognition, with the prospect of improved outcome. We assessed the performance of pulse oximetry as a screening method for the detection of critical congenital heart defects in asymptomatic newborn babies. In this systematic review, we searched Medline (1951-2011), Embase (1974-2011), Cochrane Library (2011), and Scisearch (1974-2011) for relevant citations with no language restriction. We selected studies that assessed the accuracy of pulse oximetry for the detection of critical congenital heart defects in asymptomatic newborn babies. Two reviewers selected studies that met the predefined criteria for population, tests, and outcomes. We calculated sensitivity, specificity, and corresponding 95% CIs for individual studies. A hierarchical receiver operating characteristic curve was fitted to generate summary estimates of sensitivity and specificity with a random effects model. We screened 552 studies and identified 13 eligible studies with data for 229,421 newborn babies. The overall sensitivity of pulse oximetry for detection of critical congenital heart defects was 76·5% (95% CI 67·7-83·5). The specificity was 99·9% (99·7-99·9), with a false-positive rate of 0·14% (0·06-0·33). The false-positive rate for detection of critical congenital heart defects was particularly low when newborn pulse oximetry was done after 24 h from birth than when it was done before 24 h (0·05% [0·02-0·12] vs 0·50 [0·29-0·86]; p=0·0017). Pulse oximetry is highly specific for detection of critical congenital heart defects with moderate sensitivity, that meets criteria for universal screening. None.

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Patient seen for croup with stridor, including performance of pulse oximetry and Decadron administration

The pulse in reflectance pulse oximetry: Modeling and experimental studies

Reflectance pulse oximetry permits the use of alternative monitoring sites such as the face or torso, and is the approach commonly employed in fetal pulse oximetry systems. The purpose of this study is to investigate the impact of assumptions about the nature of arterial pulsatility on the calibration of such systems. Monte Carlo simulations of reflectance pulse oximetry were run on a six-layer tissue model, varying depth and magnitude of the arterial pulse. SpO2 readings on and off the femoral artery obtained during desaturation studies in newborn piglets were compared to predictions. Results. Monte Carlo simulation results clarified the difference between deep and shallow pulsatility found with photon diffusion models, agreeing with earlier in vivo observations. Significant overestimation of SpO2 <75% and slight underestimation >75% is expected if a sensor is placed on a highly pulsatile site. The on- and off-artery SpO2 readings recorded during desaturation in the newborn piglet follow the model predictions. The sensitivity of reflectance pulse oximetry calibration to the depth and magnitude of arterial pulsatility reinforces the observation that monitoring site selection is of importance in optimizing reflectance pulse oximetry performance, particularly fetal pulse oximetry. Sites with palpable pulsatility should be avoided.

Motion resistant pulse oximetry in neonates

Background: Pulse oximetry is widely used in neonates. However, its reliability is often affected by motion artefact. Clinicians confronted with questionable oxygen saturation (Spo2) values often estimate the reliability by...